Western Digital Elements
Western Digital Elements is a line of portable external hard drives sold by Western Digital. As of 2018, sizes range from 4 TB to 500 GB and support USB 3.0 and are backward compatible with 2.0. It comes in two sizes with the larger form being about the size of a man's wallet. It comes pre-formatted with NTFS and is ready to go out of the box.
I bought my USB 3.0 500 GB, around 2014, which was on the large end at the time. This has been a very sturdy hard drive. I've used it almost every day since then, and I have dropped it several times, even to the point of popping open the enclosure, but it continues to run just fine. I would recommend this to anyone who wants a no-nonsense portable hard drive.